98 TJ third gear and overdrive shifting problem

[DaganS]

That's a good find. It's possible that the TV cable plus OP's favorite throttle position is such that it wants to downshift & then upshift. The amount of RPM change he mentioned in the 2nd post is more consistent with 2nd to 3rd than with the TC lockup.

As a test, disconnect the end of the TV cable from the throttle lever on the intake. Drive it normally. It won't shift how you're used to, but it may hold 3rd gear better. Do that test & report back.

I’m not sure if your replying to mine or not but it’s not so much of up shifting or downshifting although it does feel like it is but I’ll have a steady cruising speed and the rpm’s will randomly start jumping and falling even if I hit bumps in the road. Then the next day it’s completely fine till later in the afternoon when it’s been drove all day

 

[Jerry Bransford]

That's a good find. It's possible that the TV cable plus OP's favorite throttle position is such that it wants to downshift & then upshift. The amount of RPM change he mentioned in the 2nd post is more consistent with 2nd to 3rd than with the TC lockup.

As a test, disconnect the end of the TV cable from the throttle lever on the intake. Drive it normally. It won't shift how you're used to, but it may hold 3rd gear better. Do that test & report back.

X2, the CV cable may be adjusted too tightly. It should just be taut/no slack and not actually pulling the cable that connected between the throttle lever and transmission. It's length is adjusted at the throttle body by releasing its lock which is a small white plastic clip that is gently pulled back 3/8" or so. Then moving the black cable sheath in or out so the inner cable is just taut.

 

[hear]

Does this RPM change come with an increase or decrease in power? If it happens when you go over bumps I’m wondering if it isn’t an electronic problem with the tach.

 

[NskLJ]

It feels harsh when the rpm’s are bouncing around it feels like it’s actually up shifting and downshifting as the rpm’s bounce around. It’s a brand new rebuilt transmission but I’m going to take it back

Oh it’s just been rebuilt. Take it back and road test it with the mechanic. Show him how you drive and the concern you are having. Could be an adjustment, could be converter, could be something in the valve body.

 

[DaganS]

Does this RPM change come with an increase or decrease in power? If it happens when you go over bumps I’m wondering if it isn’t an electronic problem with the tach.

It actually feels like it’s shifting there’s in increase in engine power from it going into higher rpm’s then falling back down

 

[Brianj5600]

I also cruise it around 2000-2200 rpm’s and it jumps up to 2500-2900 and it’s just back and forth it feels like it’s having trouble shifting into overdrive I’m not sure

One thing to consider is that the engine may not be making enough torque at the tires with 33s and stock gearing. What speed are you going at the RPMs you posted? What gear ratio is in the axles?

 

[Jerry Bransford]

I also cruise it around 2000-2200 rpm’s

Just noticed that, those cruising rpms are too low, you're lugging the engine which not good for the engine or your mpg. I'd regear to 4.11 to get the rpms background up to where they should be.

 

[DaganS]

One thing to consider is that the engine may not be making enough torque at the tires with 33s and stock gearing. What speed are you going at the RPMs you posted? What gear ratio is in the axles?

50-55 2000rpm 60-65 2300 rpm with stock gear ratio